1. (use a diagram to help you explain)
Lesson Starter
WRITE IN SENTENCES
Describe what happens to the particles when you:
a) Heat a substance up
b) Cool a substance down
(use a diagram to help you explain)

2. What’s the matter?
Lesson 8

3. Lesson 8 – Learning Intention
Expansions and contractions

4. Aim of the experiment
We know that particles move faster when we give them more energy (by heating them up) Does this make the material (being heated) change in any way?

5. Apparatus Goggles Bunsen burner
Metal ball and ring (or clamp and T bar)
Clamp stand

6. Method Use the clamp stand to hold the ring (or clamp) securely
Check the ball fits through the ring (or the t-bar fits into the clamp)
Light the Bunsen burner and turn it to the warmest flame
CAREFULLY roast the ball (or T-bar) for 1 minute
Now try and see if it still fits- BE CAREFUL
Hold the metal under the cold tap for a few minutes
Check to see if it fits
Turn off the Bunsen and let everything cool down

7. Safety Roasting hot metal is very dangerous
What safety precautions do we need to take?

8. What did you see? Why do you think this happened?
Results
What did you see? Why do you think this happened?

9. Conclusion
When we heat the particles up, we gave them more energy so they moved further apart causing the material to get bigger
This is called EXPANSION

10. Conclusion
When we cooled the metal back down, the particles didn’t have as much energy so couldn’t spread out as much
The material got smaller
This is called CONTRACTION

11. Particles The particles themselves DO NOT CHANGE SIZE
It is the space between them that gets bigger or smaller

12. Summary
On the post it provided, write your name and a summary of what you have learned about contraction and expansion